Various three-dimensional displays for presenting three-dimensional images have been developed (see Patent Document 1, for example.) In a three-dimensional display, a three-dimensional image is generally presented in a space in front of a screen, a space above the screen or the like.
The three-dimensional display described in Patent Document 1 has a conical light ray controller. The light ray controller is arranged such that a base of the cone opens on a reference plane. A rotation base to which a plurality of scanning projectors are fixed is provided below the reference plane. Each scanning projector irradiates an outer peripheral surface of the light ray controller with a light ray group including a plurality of light rays from outside of the light ray controller while rotating on the rotation base about a rotation axis. The light ray controller transmits each light ray emitted by each scanning projector without diffusing the light ray in a circumferential direction. Thus, a three-dimensional image is displayed above and inside of the conical light ray controller.
[Patent Document 1] JP 2011-48273 A